Barbershop harmony is four-part, unaccompanied, close-harmony singing, with melody in the second voice, called the Lead. The Tenor harmonizes above the lead singer, the Bass sings the lowest notes and the Baritone provides the in-between notes to form consonant, pleasing chords.
Barbershop is a "melting-pot" product of African-American musical devices, European hymn-singing culture and an American tradition of recreational music.
Here are some Barbershop Arrangements you can try:
Down By The Old Mill Stream Shine On Me
Hello! My Baby Wait Till the Sun Shines, Nellie
I Love You Truly You Tell Me Your Dream
I Want a Girl You're As Welcome As the Flowers in May
Let Me Call You Sweetheart You're The Flower of My Heart, Sweet Adeline
All sheet music listed here is in the Public Domain
More songs, recordings and information about Barbershop singing is available on the Barbershop Harmony Society web page located at: http://www.barbershop.org/